So, if you can achieve your goal with temporary hardship, if the goal is honest then you will definitely start getting results after achieving the goal. In case of Bitcoin investment, you take temporary pains to take your investment to a certain goal, after achieving the goal, you will start reaping the results from there.
I will view "Hardship, Pain" you say as the Price that investor/Bitcoiners who have low finance ends gotta pay to reach what they aim for. As I would always say that what differentiate some investor from others is there perception about Bitcoin... For an investor that values it such investor will create and align with system that can help him to reach this goal while the other tries to gamble, chill out, call Bitcoin scam, etc.
I have a little different approach to bitcoin from yours. It was before I was thinking in your direction but now a lot have changed for the better and I can boldly say that I am enjoying the process more. Before, I had this mindset that I had to deny myself everything, even cut down on the quality of food and other basic needs to be able to invest in bitcoin. I think this approach is not the best as it will make the journey stressful and full of fear. It is never wise to pay unbearable price to invest in bitcoin so that the aim of the investment is not defeated. There is nothing bad with investing little amount per time instead of starving yourself to buy bitcoin.
As little as $15 per week, which is affordable for anyone with a good source of income, and spread across several years will yield something vey big.
The $15 is even big for someone who is struggling to invest with a low income generation. at Least as we have learnt so far, $5-10 may as well be good for someone who is overly trying to manage himself without starving to achieve bitcoin accumulation. Bitcoin accumulation is almost a life time journey and shouldn't be done in a hurry to the extent of starvation. Though we are saying thesame thing and mine is not different from your own but my point is that if the $15 which you advise may still be much for the person to invest h/she may decide to reduce it to achieve a better result of accumulation and a good dieting and may Increase to $15 -20-50 per week when such person may have gotten a better and desirable job. Bitcoin accumulation should be done effortlessly, seamlessly and tiredlesly.